No delivery and no response to emails

I ordered a book through them at the beginning of the year, still have not received the book. Emailed them to let them know that my address had changed yet they still sent to the book to my old address. Emailed countless times to arrange delivery, no response. Emailed countless times to cancel my memebership and have yet to hear from them. I am so tired of getting sms's demanding a payment of R74 for a book that I did not order but yet they insist on sending it, should they have checked their emails from me they would have seen that I wanted to cancel my membership before they wanted to send me the book. I have ignored their sms's as I will not pay for such shocking service. They are quick to demand payment but will not read my emails asking them to cancel my membership. I have now had it with them!!!